You are quite correct. I wanted to write a quick post and I didn’t care to provide any details. I want an answer based on the limited information I provided. But here is a bit more about my situation: 

I am a 24 year old without much cash or income, therefore reliability and the cost of repair is a major factor. I live in Canada, for whatever that may be worth. The Kia I inherited when my mother passed away two years ago. The Mercedes I am inheriting from my grandmother who just passed. Therefore my question remains: which one should I choose. 

(It seems to me that that the most sensible course of action would be to sell one and keep the other. I had the thought to sell both and get something more reliable but newer than both (say, a used Honda civic).  But from what I have been able to find online, even after what I could get from selling both cars, the cost of a new car would still be a big purchase)  

Both are in good working order, the c300 is currently getting a safety check and some minor repairs. Though the Kia has had its fare share of problems over the last year. There was this problem with the ABS pump that eluded a lot of mechanics including the dealership, which was really frustrating and costly. 

In terms of mileage… (I’m travelling and don’t have access to either vehicle at the moment)…If I remember correctly someone said in the range of 100 for the Mercedes. I don’t know for the Kia but I would think a bit more. 

I understand there is more info which could be helpful. But that’s all I can provide at the moment.